temperature compensation crystal oscillator

has anyone ever replaced the clock crystal with a "temperature compensation crystal oscillator" or tcxo I believe for short..... I am I need of ridiculous timing accuracy but I am finding little info on this topic anyone out there have any ideas or sugestions

A long time ago (somewhere in the eighties) i saw an Elektor article mentioning a "furnace".
That was a thermal isolated metal chamber heated by a transistor (i think).
(The transistor and the oscillator were inside the chamber).
By keeping the temperature at some higher level as the surroundings, one didn't need to do extra compensation i guess.
I'm not sure what the article was telling but i remember it was mentioned.

Must be better / easier ways nowadays.

Does anyone know how well arduino uno r3 keeps time......... I am using this board to run a world clock and am needing very accurate time over a long period.. which the uno r3 may be able to provide I am just wanting to make sure....... I just don’t want to be losing seconds and in a week be off by minuets

This has recently been discussed.

yes I see something was discussed but I still don’t feel like that answered my question really...if I let arduino uno r3 run for say 2 months is it still accurate within a minute..... this clock I am repairing has the capability to read time down to 1/1000 of a second is the arduino going to keep the right time at such a small reading

Just to be clear on the difference between accuracy and resolution. Being able to read a clock to a millisecond (.001 sec) describes its resolution. Being correct within a minute over two months describes accuracy. The two aren't particularly related.

Now, does this properly describe the requirements? Accurate to one minute over two months, and millisecond resolution?

Yes this is correct I need both..... more importantly is the accuracy I have a sketch written and am currently running my most sensitive clock to see the accuracy of my current set up..... so far after running all day it is right on the money I was just hoping to get some idea of what I can expect over a long time period

I forgot to add that these clocks are analog and are old....... originally engineered in the late 60's so I am not sure if this clock can keep up with the arduino as is this pic may help you visualize

this may work better the first pic didn't load or something

So what accuracy is needed? I don't have an R3 but last I knew, Unos had ceramic resonators which are on the order of ±0.5% accurate, which most people wouldn't find acceptable for a wall clock.

bigbuck83:
this may work better the first pic didn't load or something

Interesting looking clock! What is it used for (or maybe I should say what was it originally used for)? What technology does it use, do you have any of the original specs?

it is a world clock and this is the master I have 15 slave clocks that run based on this main clock as for specs no I have a busted up manual that is in German so it isn’t much good I have re- wired the entire thing and am currently putting it all back together and testing but I fear the Arduino isn’t going to give me the accuracy I need over a period of time .......how do I correct this

The Maxim Integrated DS3231/32/34 RTCs are popular, they have temperature compensated crystal oscillators and are accurate to ±2ppm from 0°C to +40°C. Macetech makes an RTC based on the DS3231 called the Chronodot, it's available at several of the popular sites, Adafruit, Sparkfun, etc. etc.

well now what a nifty little gadget seems pretty straight forward I guess the chronodot is easy to use I am using 2 L298d H-bridges what tutorials could you recommend.........I would like to see it used if posssible

Yes nifty indeed! Do you mean tutorials on the Chronodot, or on the H-bridges?

oh sorry the chronodot and I will be using it with my h-bridges basicly I am not sure how to hook it up with what I have hooked up already........ does it use a arduino all to its own or is it applied to what I have already.....................just not sure what to do with it........ I will need two of them unless 1 chronodot can be hooked up to 2 uno's

Just google for "real-time clock" and Arduino. The Chronodot/DS3231 connects to the I2C bus which is pins A4 and A5 on an Uno. There are libraries available to make the programming a bit easier but it's not that difficult to just use the Wire library which does general I2C communication. Another very popular but less accurate RTC is the DS1307, you'll also find a ton of information on those. Internally, the registers for the DS3231 and DS1307 are very similar, so libraries or code that works for one will often work for another. You will need one RTC for each Uno.

ok thanks very much I will do my homework If I have any questions I will definitely ask.......... I asume you have used this device before have you had any weird problems worth mentioning

bigbuck83:
ok thanks very much I will do my homework If I have any questions I will definitely ask.......... I asume you have used this device before have you had any weird problems worth mentioning

Yes I've used DS1307, DS3231 and DS3232. They're all good devices, well behaved, easy to use. I did write a library for the DS3232/31. Still working on finishing the documentation but it's available on github FWIW.

ok, after doing some reading it seems the chronodots work well with digital clocks or LCD screens but will it work with a analog clock as posted in the pic I dont seem to find much info on using an anolg clock with these devices